Electrolytes are commonly employed as a catalyst in batteries to promote the movement of ions between an anode of the battery and a cathode of the battery during charging and discharging. Electrolytes may be aqueous, gelled or dry electrolytes comprising soluble salts, acids, or bases.
During charging and discharging of a battery, in a process referred to as cycling, electrolytes may be converted into a gas as water in the electrolyte is separated into hydrogen and oxygen. Vent caps are typically employed to allow the gas to freely escape from the battery, subjecting the battery to lower fluid levels as water and the electrolytes are gradually reduced. The water vapor typically escapes through vents and valves in the vent caps.
To maintain performance of the battery, it is necessary to periodically add water to the battery which increases maintenance costs. For example, a battery with lower fluid levels may not charge to a full capacity, and may indicate high voltages during charging, as the battery is unable to draw current. Therefore, it is necessary to properly maintain a desired level of fluid within the battery.
Certain vent caps are known to increase an amount of time between maintenance periods required to add water to the batteries. Examples of vent caps or similar devices are shown and described in U.S. Pat. Nos. 8,999,565, 9,461,287, and U.S. Pat. Appl. Pub. No. 2013/0034757, the disclosures for which are hereby incorporated by reference in their entirety. For example, a battery vent cap such as the WATER-MISER™ battery vent cap manufactured by Doyle Manufacturing, Inc. is employed to minimize watering maintenance periods of the batteries by capturing water vapor before the water vapor escapes from the battery through vents formed in the battery vent cap. The vent caps include a plurality of plastic pellets to condense the water vapor and redirect or recombine the water back into the battery. A micro-porous disc may also be included to condense and capture water vapor before escaping the battery and redirect the condensed water back into the battery. While these vent caps are successful in minimizing the evaporation of water from the battery cell, there is an increasing need to further limit the evaporation of the water from the battery.
Accordingly, there exists a need in the art for an improved vent cap for recombining water to the battery.